Hi, I've made a matrix with my first row being nest numbers and my second row being a score for individuals in that nest. Row after that contain the difference in score for that individual and its neighbour - i assigned a formula to each element (thus all the columns have different lengths, but I've made them equal by putting NA in them) and my last row having the mean for each column. I was wondering if there is a way to randomly assign the score values to different nests (doing this 1000 times) and then have R calculate the new differences and store the averages in a new matrix, since bootstrapping won't work for this case. Best, Monaly. [[alternative HTML version deleted]]